Fish telemetry

A recaptured, tagged fish Red roman Tsitsikamma National Park
082 TAG FISH Just before releasing a tagged white steenbras Fish tagging team

Fish telemetry (sonic tagging) provides the means to better understand the lives of fishes in their natural environments and answer a number of key questions about their life history. Transmitters fitted with sensors that measure depth, temperature, salinity and muscle activity allow us to collect real-time data. This information is used to analyse activity patterns, movements, habitat use patterns and aspects of the physiology of tagged fishes.

Since 2003 we have been tagging selected estuarine and lagoon fish species, namely dusky kob, white steenbras, elf and spotted grunter. We use conventional tagging methods and acoustic telemetry techniques to:

  • Describe movement behaviour and habitat utilisation;
  • Establish the periodicity and duration of fish movements between sheltered coastal habitats and the sea;
  • Describe behavioural responses to the abiotic environment (e.g. temperature changes);
  • Collate fishery data with observed daily and seasonal movement trends and assess the species' vulnerability to local depletion.